At one time, the issue of whether a particular telecommunications call is a local call or a non-local call was primarily of interest to only two parties: the subscriber and the telecommunications service provider that billed the subscriber for the call. These two parties remain interested in this issue because a local call may billed differently than a non-local call. For purposes of this application, a local call is defined as a call for which the service provider charges a base fee and no extra fees such as long distance charges, toll charges, etc.
Presently, the issue of whether a particular telecommunications call is a local call is of interest to other parties as well as the subscriber and the service provider. Such other parties may include marketing and sales people who offer products and services that are used in conjunction with telecommunication services. These marketing and sales people may be interested in determining the local calling area of a subscriber in order to better target products and services to that subscriber. As used herein, a local calling area of a subscriber encompasses the geographic area that the subscriber may call with a local call. In other words, a local calling area is generally the area within which local telephone service is furnished to subscribers under a specific schedule of exchange rates and without long distance or other such charges. A local calling are may include one or more exchange service area. As used herein, the term "local calling area" is used synonymously with the following terms unless otherwise noted: local service area, limited local calling area, full local calling area, and expanded local calling area.
Thus, subscribers and telecommunications service providers remain interested in the issue of whether a particular call is a local call or a non-local call. But this interest has expanded to include marketing and sales people. Other parties as well may have their own reasons for taking an interest in a subscriber's local calling area, and in particular, whether a particular call is classified as a local call or non-local call.
Generally, a telecommunications service provider constructs and maintains extensive records to keep track of the classification of a particular call as a local or non-local call. These records are based on the organization of directory numbers that are respectively assigned to subscribers or terminating devices or lines associated with a subscriber. A directory number, commonly referred to as a telephone number, is the number that is dialed or input by a calling party or an originating device to place a call to a terminating device associated with the dialed directory number. The dialed directory number provides information with respect to the routing of the communication from the originating device to the terminating device. Each directory number in the North American Numbering Plan Area includes ten digits (e.g. 404-818-3720). A group of 10,000 directory numbers having the same first six digits is referred to as an "NPA-NXX". The "NPA" of "NPA-NXX" generally refers to "Numbering Plan Area" and the "NXX" generally refers to "Exchange". For example, there are 10,000 ten-digit directory numbers that start with an NPA-NXX of 404-818. Thus, the NPA-NXX of 404-818 represents these 10,000 directory numbers. Of course, not all of these directory numbers may be assigned to subscribers. The first six digits of a ten digit directory number are also referred to herein as the NPA-NXX portion of the directory number or as the NPA-NXX designation or part of the directory number.
Generally, all of the lines that are associated with directory numbers that have a common NPA-NXX are served by the same switch in a telecommunications network. An exception to this generalization is discussed below after this general explanation. Reference again is made to the generalization that directory numbers having a common NPA-NXX are served by the same switch in a telecommunications network. For example, all of the lines that are associated with directory numbers that have an NPA-NXX of 404-818 are served by the same switch. Further, this switch may serve lines that are associated with other NPA-NXXs. For example, the switch serving the 404-818 lines also may serve lines with the following NPA-NXXs: 404-515, 404-656, and 404-749. Thus, when a calling party places a telephone call, the first six digits of the dialed directory number (i.e., the NPA-NXX portion) identify the switch that serves the line associated with the desired subscriber or terminating device. As used herein, the term "switch" may also include a central office or end office. In an Advanced Intelligent Network (AIN), a switch also may be referred to as a service switching point (SSP). When a call originates on a line served by a switch, then the switch may be referred to as an originating switch. The NPA-NXX portion of the directory number associated with the line or device from which the call originates may be referred to as an originating NPA-NXX. Of course, the device from which the call originates may be referred to as the originating device. Similarly, when a call terminates on a line served by a switch, the switch may be referred to as a terminating switch. The NPA-NXX of the directory number associated with the line or device to which the call is directed may be referred to as the terminating NPA-NXX. Of course, the device to which the call is directed and to which the call terminates may be referred to as the terminating device.
An exception was noted to the generalization that all of the lines that are associated with directory numbers that have a common NPA-NXX are served by the same switch in a telecommunications network. The noted exception to this generalization is the case of "split-offices". A split-office may also be referred to as a "split-switch." For example, in a large local calling area that crosses state borders such as in Chattanooga, Tenn. or Columbus, Ga., two or more switches may serve the same NPA-NXX. In particular, switch A may serve a first group of directory numbers having a certain NPA-NXX and switch B may serve a second group of directory numbers having the same NPA-NXX as that of the first group served by switch A. Thus, service of this certain NPA-NXX is split between switch A and switch B. The existence of these split-offices aggravates the problem of determining the local calling area of any particular directory number or NPA-NXX. This problem is aggravated by the existence of split-offices because, inter alia, a local calling area for a particular NPA-NXX may not be determined by reliance on the area served by the switch that serves the particular NPA-NXX.
Principally for billing purposes, a telecommunications service provider must be able to determine whether a call from a device associated with a specific NPA-NXX is a local call or a non-local call. If the call is a local call, the service provider bills the subscriber at a predetermined rate for the call. If the call is a non-local call, then the service provider may bill the subscriber at a different rate for the call. A service provider generally makes this determination of whether a call is a local call or a non-local call by consulting a table known to those skilled in the art as a Combo file or table or an Originating NPA-NXX/Terminating NPA-NXX file or table. This Combo file is constructed and maintained to accommodate this requirement of determining whether a call from a device assigned a specific NPA-NXX as part of its directory number is a local call or a non-local call. A typical Combo file includes millions of entries. Each entry in the Combo file usually includes at least two parts: (1) an originating NPA-NXX; and (2) a terminating NPA-NXX. By these parts, each entry represents a call that may be made as a local call from a device associated with a directory number having the originating NPA-NXX to another device associated with a directory number having the terminating NPA-NXX. For ease of explanation, this description refers to "a call from an originating NPA-NXX" as short-hand for "a call from an originating device associated with a directory number including the originating NPA-NXX". this description also refers to "a call to a terminating NPA-NXX" as short-hand for "a call to a terminating device associated with a directory number in the terminating NPA-NXX".
It is important to note that a Combo file typically includes information in addition to originating and terminating NPA-NXX. Such as band information or expanded billing information. This additional information has not been described in this specification for sake of simplicity and clarity of explanation.
More particularly explained, each of the entries in the Combo file is constructed in two parts. First, an originating NPA-NXX is entered as an NPA-NXX associated with a specific directory number used in the geographic area served by the service provider. Second, a terminating NPA-NXX is entered as an NPA-NXX associated with directory numbers used in the geographic area served by the service provider and to which a call from the originating NPA-NXX is deemed to be a local call. From these two-part entries in the Combo file, a call from a particular device may be classified as a local call or a non-local call. For example, assume that a call is made from a device associated with a directory number having a specific NPA-NXX, which is referred to as the originating NPA-NXX. This call is made to another device associated with another directory number having another NPA-NXX, which is referred to as the terminating NPA-NXX. To classify this call as a local call, the Combo file is checked to determine whether there is an entry that corresponds to the originating NPA-NXX and terminating NPA-NXX associated with the call. In particular, each of the entries in the Combo file must be checked to determine whether there is such a matching entry. As noted above, a typical Combo file includes millions of entries. Thus, to classify a call as a local call, these millions of entries must be checked against the originating NPA-NXX and terminating NPA-NXX of the call. If a matching entry is found amongst the millions of entries, then the call is classified as a local call. Otherwise, if no matching entry is found, then the call cannot be classified as a local call. Other steps may have to be taken with respect to the classification of this call.
As noted, a telecommunications service provider constructs this Combo file to keep track of calls that may be classified as local calls versus non-local calls. Even though this Combo file keeps track of the classification of calls between originating NPA-NXXs and terminating NPA-NXXs, this Combo file includes millions of entries. These millions of entries cause significant problems with respect to the storage and use of this Combo file. With so many entries, this Combo file occupies a lot of memory space in the device storing this Combo file. Thus, this Combo file may not be readily stored on devices that have limited storage space. As such a large occupier of memory, this Combo file may not be readily transferred to other devices. Also with so many entries, this Combo file is difficult to search. As noted above, to classify a call as a local call, the Combo file is checked to determine whether there is an entry that corresponds to the originating NPA-NXX and terminating NPA-NXX associated with the call. With millions of entries to check, a check for a matching entry may take a relatively long time. The length of time used in searching the Combo file may be unacceptable for several reasons.
These enumerated problems with the Combo file have plagued the telecommunications service providers which use such Combo files. But with the increased interest from others such as marketing and sales people in the issue of the classification of calls from subscribers as local or non-local calls, these problems with the Combo files are exacerbated. Generally, these interested parties such as marketing and sales people do not have the same types of large scale computing devices or facilities as used by telecommunication services providers. Thus, these interested parties suffer further from the problems of Combo files occupying large amounts of memory, being non-readily transferable, and being slow to search. These problems frustrate these interested parties in quickly and readily obtaining information about the local calling area of a particular NPA-NXX or other information that may be gleaned from a Combo file.
In sum, the issue of whether a particular call made or that may be made by a subscriber is a local call or a non-local call is of increasing interest to parties other than just subscribers and telecommunications service providers. The Combo files used to classify a call as a local or non-local call based on the originating NPA-NXX and terminating NPA-NXX associated with the call have proved inadequate in certain respects for use by these other parties and by telecommunications service providers. The large sizes of these files and tables have made them difficult to store, to transfer and to search in a quick and efficient manner.
Therefore, there is a need for an improved method and system for determining the classification of a call as a local call or a non-local call.
There is a particular need for a method and system for determining the classification of a call as a local call or a non-local call based on the originating NPA-NXX associated with a call.
There is also a particular need for a method and system for obtaining local calling area information based on a particular NPA-NXX of a directory number.
There is yet another particular need for a method and system for obtaining information regarding calls that are classified as local calls from a particular NPA-NXX.
There is a further need for a method and system for determining the classification of a call as a local or non-local call and the local calling areas of any particular NPA-NXX that may be used in connection with general purpose computing devices such as personal computers, without occupying large amounts of memory of such devices, by being readily transferable between such devices, and by being readily searched by such devices.